According to environment experts, travelling by trains can have a positive impact on climate change. Partly in keeping with this vision, possibilities of running night sleeper trains between the United Kingdom and continental European countries via the Channel tunnel are also being contemplated. However, the running of trains according to the stringent safety rules implemented through the Channel tunnel also has to be aligned with train operations, say travel experts. Also, safety concerns, the rolling stock, facilities, etc. required for these trains may result in high costs. Hence, if trains will be able to compete with budget airlines on ticket prices also has to be considered before implementing the project.